Insight into the effects of the CO2/H2O activation and Ce redox cycle over ni/CeO2/hydrotalcite catalyst surface on biogas Bi-reforming for methanol friendly syngas

The use of green biogas as a raw material for producing methanol-friendly syngas (H 2 /CO ≈ 2) for one-step methanol synthesis has gained significant attention. However, developing efficient catalysts with high activity and stability remains challenging, as they often face issues with stability and carbon deposition. This study presents a Ni/CeO 2 /HT catalyst designed for high activity and long-term stability by leveraging the Ce redox cycle and strong interactions between Ni-CeO 2 and hydrotalcite (HT). The catalyst benefits from abundant oxygen vacancies generated by the Ce 3+ - Ce 4+ pathway, enhancing its ability to activate CO 2 and H 2 O and providing excellent coke resistance. Comprehensive analyses of CO 2 /H 2 O adsorption and carbon elimination mechanisms were conducted using techniques such as in situ H 2 -TPR, CO 2 /H 2 O-TPSR, in situ CH 4 -TPSR, CO 2 /H 2 O-TPO, and FTIR. The Ni/CeO 2 /HT catalyst outperformed others in CO 2 /H 2 O adsorption and CH 4 activation capacity, promoting the generation of active oxygen species and effectively removing coke precursors, thereby improving resistance to Ni sintering and carbon deposition. At 750 °C and a weight hourly space velocity (WHSV) of 32,400 mLg Cat −1 h −1 , it achieved CH 4 and CO 2 conversions of 93 % and 66 %, respectively, with long-term stability exceeding 200 h.